5 
notice the rocks and the shape of the country, and to try and pick 
up fossils, and so confirm his theory. 
The Canal Bill passed the Houses of Parliament in the same 
year (1794), and in the preliminary surveys, and also in the making 
the canal itself, Smith was led to arrive at two of the greatest facts. 
in geology which more than 100 years of subsequent work has not 
only failed to upset, but tended to confirm. 
These facts are, first, that the several layers of rock from the 
New Red Marl (Trias) upwards followed one another in regular. 
and orderly superposition, one overlying the other, and a/ways 
following the same order: and secondly, that the fossil-organisms 
such as shells, corals, and so forth, found in each are characteristic 
(as a rule) of that particular formation, and serve to identify the 
beds wherever they have been met with. 
“ For six years,” he writes, “I was Resident Engineer on the 
Somersetshire Coal Canal, which put my notions of coal stratifica- 
tion to the éest of excavation; and I generally pointed out to 
contractors and others, who came to undertake the work what the 
various parts of the canal would be dug through. But the great 
similarity of the rocks of Oolite on and near the ends of the canal 
towards Bath, required more than superficial observation to 
determine whether they were composed of one, two, or even of 
three kinds of Oolite rock.” 
William Smith was thus led to direct his careful attention to 
the characteristic fossils which he found embedded in each 
separate rock-formation. 
“This discovery of a mode of identifying the strata by the 
organised fossils respectively embedded therein, the sharpness of 
these in their primitive sites contrasted with those rounded and, 
water-worn in gravel, led to the most important distinctions.” 
(Phil. Mag.,” 1833). 
Smith remained in the service of the Canal Company till June, 
1799, and in this year he drew up his first table of the order of 
succession of the British strata, although not published until long 
